Field of the Invention
The present invention relates to a method for catalyst heating control, and more particularly, to a method for catalyst heating control configured for improving fuel efficiency by deciding an aging level of a catalyst through a temperature of exhaust gas determined using a lambda sensor and determining an appropriate time of a catalyst heating period depending on the aging level of the catalyst.
Description of Related art
A temperature of exhaust gas exhausted from an engine is a very important factor in developing performance of the engine, a catalyst, or the like.
In the case in which the temperature of the exhaust gas is excessively high, damage to hardware of the engine, damage to the catalyst, and the like, may be caused. Particularly, in an engine in which a turbo charger is mounted, a control of the exhaust gas is required. In addition, in the case of intending to calculate a mass of the exhaust gas, the temperature of the exhaust gas is required.
Therefore, the temperature of the exhaust gas, which is a main factor used to limit the performance of the engine or limit fuel injection depending on protection of the hardware of the engine, activation of the catalyst, and the like, may be an input variable necessary to control the engine.
Meanwhile, a pollutant of the exhaust gas exhausted from the engine is removed while the exhaust gas passes through a purifying device such as a catalyst converter, or the like. Then, the exhaust gas of which the pollutant is removed may be exhausted to the air.
A catalyst performing an oxidation-reduction reaction to the exhaust gas is embedded in the catalyst converter, and a temperature of the catalyst should be an activation temperature or more in order to activate the catalyst.
In addition, catalyst heating control for shortening a light-off temperature (LOT) arrival time of the catalyst is performed.
However, in a method for catalyst heating control according to the related art, the same control condition of a catalyst heating period is used regardless of an aging level of the catalyst. That is, since a fresh catalyst and an aging catalyst are used without being distinguished from each other, appropriate catalyst heating control depending on an aging level of the catalyst is not performed. Therefore, purifying efficiency of the exhaust gas depending on the aging level of the catalyst is decreased, and fuel efficiency is deteriorated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.